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Related papers: Chemically peculiar stars and their temperature ca…

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We have executed a survey of nearby, main sequence A, F, and G-type stars with the CHARA Array, successfully measuring the angular diameters of fortyfour stars with an average precision of ~ 1.5%. We present new measures of the bolometric…

The derivation of the effective temperature of a star is a critical first step in a detailed spectroscopic analysis. Spectroscopic methods suffer from systematic errors related to model simplifications. Photometric methods may be more…

Solar and Stellar Astrophysics · Physics 2015-06-15 Julián Muñoz Bermejo , Andrés Asensio Ramos , Carlos Allende Prieto

The determination of fundamental parameters of stars is one of the main tasks of astrophysics. For magnetic chemically peculiar stars, this problem is complicated by the anomalous chemical composition of their atmospheres, which requires…

Solar and Stellar Astrophysics · Physics 2019-07-12 A. Romanovskaya , T. Ryabchikova , D. Shulyak , K. Perraut , G. Valyavin , T. Burlakova , G. Galazutdinov

A new extensive grid of synthetic Str{\"o}mgren colors and bolometric corrections is presented for F-M type dwarf and giant stars having 3000K $\leq$ T$_{\rm{eff}}$ $\leq$ 8000K, 0.0 $\leq$ log $g$ $\leq$ 5.0, and -3.0 $\leq$ [Fe/H] $\leq$…

Astrophysics · Physics 2007-05-23 James L. Clem , D. A. VandenBerg , F. Grundahl , R. A. Bell

We present an empirical calibration of the physical parameters of A, F and early G-type stars of luminosity class V. We have used a statistical approach based on a sample of about 15 000 stars having both uvby-Str\"omgren photomerty (Hauck…

Solar and Stellar Astrophysics · Physics 2012-12-14 Giannina Dalle Mese , Omar López-Cruz , William J. Schuster , Carlos Chavarría , J. Gabriel García

About 10% of upper main sequence stars are characterised by the presence of chemical peculiarities, often found together with a structured magnetic field. The atmospheres of most of those chemically peculiar stars present surface spots,…

Solar and Stellar Astrophysics · Physics 2015-06-03 K. T. Wraight , L. Fossati , M. Netopil , E. Paunzen , M. Rode-Paunzen , D. Bewsher , A. J. Norton , G. J. White

Deriving metallicities for solar-like stars follows well-established methods, but for cooler stars such as M dwarfs, the determination is much more complicated due to forests of molecular lines that are present. Several methods have been…

By means of numerical experiments we explore the application of interferometry to the detection and characterization of abundance spots in chemically peculiar (CP) stars using the brightest star eps~Uma as a case study. We find that the…

Solar and Stellar Astrophysics · Physics 2015-06-22 D. Shulyak , C. Paladini , G. Li Causi , K. Perraut , O. Kochukhov

The application of the Stromgren photometric luminosity calibrations to different types of CP stars is reexamined in the light of the new Hipparcos data. A first attempt is made to use the LM statistical parallax method (Luri et al., 1996)…

We compile a sample of Sun-like stars with accurate effective temperatures, metallicities and colours (from the UV to the near-IR). A crucial improvement is that the effective temperature scale of the stars has recently been established as…

Astrophysics · Physics 2009-11-13 Johan Holmberg , Chris Flynn , Laura Portinari

(Abriged) A new grid of theoretical color indices for the Stromgren uvby photometric system has been derived from MARCS model atmospheres and SSG synthetic spectra for cool dwarf and giant stars. At warmer temperatures this grid has been…

Astrophysics · Physics 2009-11-10 J. L. Clem , D. A. VandenBerg , F. Grundahl , R. A. Bell

We present an empirical calibration of the uvby-beta photometric system to determine the intrinsic colours and indices and the astrophysical parameters of the underlying star, valid for Be stars earlier than B5. The procedure allows the…

Astrophysics · Physics 2007-05-23 Juan Fabregat , Jose M. Torrejon

Isochrones for ages > 4 Gyr and metallicities in the range -2.5 < [Fe/H] < +0.3 that take the diffusion of helium and recent advances in stellar physics into account are compared with observations in the Johnson-Cousins BV(RI)_C photometric…

Solar and Stellar Astrophysics · Physics 2015-05-20 Don A. VandenBerg , Luca Casagrande , Peter B. Stetson

This talk is devoted to the statistical analysis of the new catalogue of Chemically Peculiar stars compiled from papers, where chemical abundances of those stars were given. The catalogue contains chemical abundances and physical parameters…

Solar and Stellar Astrophysics · Physics 2018-12-13 S. Ghazaryan , G. Alecian , A. A. Hakobyan

We present new calibrations of stellar parameters of O stars at solar metallicity taking non-LTE, wind, and line-blanketing effects into account. Gravities and absolute visual magnitudes are derived from results of recent spectroscopic…

Astrophysics · Physics 2009-05-29 F. Martins , D. Schaerer , D. J. Hillier

A new all-sky catalogue of all available uvbybeta measurements from the literature was generated. The uvbybeta photometric system is widely used for the study of various Galactic and extragalactic objects. It measures the colour due to…

Solar and Stellar Astrophysics · Physics 2015-07-22 Ernst Paunzen

I study the importance of the accurate calibration of photometric systems in order to produce meaningful comparisons between the observed colors + magnitudes and model SEDs. Possible sources of errors are discussed and two examples are…

Astrophysics · Physics 2007-05-23 J. Maíz Apellániz

We use moderate-resolution optical spectrophotometry and the new MARCS stellar atmosphere models to determine the effective temperatures of 74 Galactic red supergiants. From these we find a new effective temperature scale that is…

We present a new calibration of optical (UBV, Stromgren, uvby-beta, and Geneva) and near IR (Johnson RIJHK and 2MASS) photometry for B and early A stars derived from Kurucz (1991) Atlas model atmospheres. Our sample of stars consists of 45…

Astrophysics · Physics 2009-11-10 E. L. Fitzpatrick , D. Massa

We have summarized all Delta a measurements for galactic field stars (1474 objects) from the literature published over more than two decades. These measurements were, for the first time, compiled and homogeneously analyzed. The Delta a…

Astrophysics · Physics 2009-11-11 E. Paunzen , Ch. Stuetz , H. M. Maitzen